Comet pushrod length

craig

Well Known and Active Forum User
VOC Member
I am having to seek out shorter pushrods to allow both the ET27 tappet adj to clear the ET24 screw on caps. Right now i have 5 7/8 on the intake and 5 15/16 on the exhaust, these will not allow ET27 to clear the caps. So i am seeking 1/16" shorter? Or should they be shorter to allow more clearance?
The cam is marked 2 R and looks like new. Head is NOS (not repro).

If the ET27 adj were socket head or slotted, this problem might not occur. Should I modify the ET27? Commonly done with mk2 cams?
thanks for any help
Craig
 

Bill Thomas

Well Known and Active Forum User
VOC Member
Hello Craig,Thats what I do, I grind the Hex' Down all round, then make the top fit a 2BA spanner, Bit of a bodge but no cost and quick, or you can buy Socket head type. Good Luck, Bill.
 

chankly bore

Well Known and Active Forum User
Non-VOC Member
While you are at it.check that your lower guides have been shortened to accomodate the greater lift of mark 2 cams.
 

timetraveller

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VOC Member
And as I have mentioned before in these esteemed pages it is worth checking that the cut outs in the top of the piston have a large enough diameter. Use Plasticine on top of the piston and then turn the engine over a couple of times to see just how near the valves are getting to the top of the piston. Tedious yes, but a lot cheaper than bent valves or worse.
 

craig

Well Known and Active Forum User
VOC Member
Guides are shortened as required, I actually got both valves at max open and tested for addtional clearance, probably 0.100" The answer at this time appears to be simply trimming the adjuster hex off, cutting a slot for screwdriver...plenty of clearance now! I would rather have socket head adjust , i will order some. I cut the top off a valve cap for a view port...works great!
Craig
 
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